Hyper production of an extra cellular, alkali stable, cellulase free and thermostable xylanase have been produced from Bacillus pumilus SV-205 using wheat bran as a substrate under solid state fermentation. Enzyme production under optimized conditions enhanced the production level from 4510 to 65,130 ± 1000 IU/g dry substrate, which was 14.4 fold as compared to production under un-optimized conditions. The application of crude xylanase was investigated in pulp bio bleaching. The bio-bleaching of kraft pulp with xylanase was the most effective at an enzyme dose of 12.5 IU/g oven dried pulp, pH 10.0 and 120 min incubation at 60 °C. Under the optimized conditions, xylanase pre-treatment reduced Kappa number by 0.8 points and increased brightness by 1.08 points as compared with the control. The pre-treatment of pulp with xylanase resulted in 19.01% reduction in chlorine consumption by maintaining the same brightness as in control. These results clearly demonstrated that the B. pumilus SV-85S xylanase was effective as a pulp bio-bleaching agent. The decrease in chlorine consumption by pre-treatment of pulp with xylanase apparently made the bio-bleaching process not only economical but also eco-friendly. The xylanase from B. pumilus SV-205 exhibit remarkable properties which are suitable for application in paper pulp bleaching and an elevated production of xylanase by B. pumilus SV-205 under solid state fermentation over wheat bran, a cheap and easily available agro-residue would apparently reduce the enzyme cost substantially.

Graphic Abstract

中文翻译：

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农业废料对短小芽孢杆菌SV-205的木聚糖酶生产牛皮纸浆的增产和生态友好型漂白

从短小芽孢杆菌（Bacillus pumilus）中已大量生产了额外的细胞，碱稳定，无纤维素酶和热稳定的木聚糖酶。SV-205以麦麸为底物，经过固态发酵。优化条件下的酶生产使干燥底物的生产水平从4510提高到65,130±1000 IU / g干底物，与未优化条件下的酶生产量相比，提高了14.4倍。研究了粗木聚糖酶在纸浆生物漂白中的应用。用木聚糖酶对牛皮纸浆进行生物漂白是最有效的，酶剂量为12.5 IU / g烤箱干燥的纸浆，pH 10.0，并在60°C孵育120分钟。在最佳条件下，木聚糖酶预处理与对照相比可将Kappa值降低0.8点，将亮度提高1.08点。用木聚糖酶预处理纸浆可以保持与对照相同的亮度，从而使氯消耗量减少了19.01％。这些结果清楚地证明了乙。短杆菌SV-85S木聚糖酶作为纸浆生物漂白剂有效。通过用木聚糖酶预处理纸浆而减少的氯消耗量显然使生物漂白工艺不仅经济而且环保。木聚糖酶来自短小芽孢杆菌SV-205表现出显着的性能，适用于纸浆漂白，并且在小麦麸皮固态发酵下短小芽孢杆菌SV-205的木聚糖酶产量提高，一种廉价且容易获得的农业残留物显然会减少酶的成本很高。

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